Writing stylus for use in facsimile receiver equipment

ABSTRACT

THIS INVENTION RELATES TO AN IMPROVED STYLUS WHICH IS USED IN A FACSIMILE RECEIVER HAVING ONE OR MORE WRITING STYLI, THE WRITING STYLUS BEING OF AN IMPROVED CONFIGURATION IN WHICH THE WRITING TIP IS OF FLAT RECTANGULAR CONFIGURATION AND OF A HARD COMPOSITION ALLOY MAKING IT MORE DURABLE AND LESS LIKELY TO PRODUCE DAMAGE TO THE INSCRIPTION SURFACE IN THE RECEIVER. THE WRITING TIP HAS UNIQUE RAKE AND ENTRY ANGULARITY SO THAT IT CAN BE MORE EASILY MATCHED WITH ITS COMPANION STYLUS, THEREBY REDUCING THE INCIDENCE OF PHASING PROBLEMS IN THE OPERATION OF THE FACSIMILE RECEIVER.

Feb. 2, 1971 E. J. OKLESHEN WRITING STYLUS FOR USE IN FACSIMILE RECEIVER EQUIPMENT Filed Feb. 24, 1969 1 2 Sheets-Shet 1 JNvENToR ERNEST J. OKLESHEN J EFFERSE AH Vouma orneys Feb. 2, 1971 E. J. OKLESHEN WRITING STYLUS FOR USE IN FACSIMILE RECEIVER EQUIPMENT I Filed Feb. 24, 1969 2 Sheets-Sheet Z RAKE ANGLE INv ENTOR ERNEST J. OKLESHEN H JEFFEQSQZVOUMG AH-orneys FIG.2

United States Patent O US. Cl. 346139 7 Claims ABSTRACT OF THE DISCLOSURE This invention relates to an improved stylus which is used in a facsimile receiver having one or more writing styli, the writing stylus being of an improved configuration in which the writing tip is of flat rectangular configuration and of a hard composition alloy making it more durable and less likely to produce damage to the inscription surface in the receiver. The writing tip has unique rake and entry angularity so that it can be more easily matched with its companion stylus, thereby reducing the incidence of phasing problems in the operation of the facsimile receiver.

BACKGROUND OF THE INVENTION The writing stylus of this invention is usable in facsimile receiver equipment of the type shown in previously filed application No. 520,269, filed Jan. 12, 1966, titled, Facsimile Synchronizing System, and application Ser. No. 176,248, filed Feb. 22, 1962, titled, Facsimile Systems, both such applications being assigned to the same assignee as the present application, and both of which incorporate a stylus or styli which are carried by a rotatable yoke structure and are responsive to electrical signals to provide indications on a pressure sensitive material positioned near the rotating yoke. In these facsimile receivers the stylus bears against the pressure sensitive material such as carbon paper and transfers an imprint upon a sheet of paper which is backed in some suitable manner. The present invention is concerned with certain problems which have arisen in connection with the construction and operation of the stylus. It has been found advantageous to use a number of styli which can operate in coordination with each other so that the time of trans mission of information from a sending device to a companion receiving device can take place within a time period.

Numerous problems have arisen related to the stylus which occur because the writing tip of the stylus may have a different wear rate from the wear rate of the writing tip of its coacting stylus. Since the inscriptions produced are the result of the combined inscriptions of the respective styli it is essential that they be as nearly identical as possible in operation and construction.

Inevitably, there is at least some degree of wear of the tip of the stylus which produces the inscription and in the past, the degree of wear and the degree of differential wear of the respective styli has reduced the quality and clarity of the mark produced. A stylus must be developed having minimal wear, and to the extent that wear occurs, it must not affect the quality and phasing of the styli in such a manner as to reduce the quality of the marking produced by separate and combined usages of the styli. By reducing the incidence of wear and producing a structure in which factors of Wear are less detrimental, it is possible to more nearly achieve an identity of operation of the two different styli so that their respective markings are more closely in phase and collectively productive of intelligible and high-quality markings.

Another important consideration in the quality of the stylus in addition to the wear factor is that since the 'ice stylus oftentimes inscribes upon a piece of paper such as carbon paper it must not be destructive of the paper when it bears thereagainst to make an inscription. Obviously, should the stylus be destructive of the paper or other medium on which the marking is made, it is unsatisfactory for that very reason.

All of these foregoing considerations are present and have presented problems in the art relative to the production, servicing, and usage of facsimile receivers having one or more writing styli.

OBJECTS OF THE INVENTION It is an important object of the present invention to produce a new and improved stylus having a writing tip which can be more readily matched with the writing tip of a second stylus and whereby their phase operations are more easily coordinated resulting in less frequent mechanical phasing adjustment of the styli during their operational life.

It is a further object of the present invention to reduce the rate of wear and the effect of wear differential rate so that matched pairs of styli can be obtained in which wear is minimal and even though there be a slight differential wear this will not affect the quality of operations.

The styli can be initially matched and will maintain their match, producing high-quality inscriptions or markings during their useful life. The solution has been found to lie in a new and improved configuration of the writing tip of the stylus. Related to this object, is to extend the useful life period of styli, to decrease the effect of Wear rate and the effect of differential wear rate of styli, thus reducing the incidence of servicing and mismatching of the styli.

A further object of the present invention is to produce a durable stylus having a hard wear-resistant writing tip which is effective over a longer period of time and which will nevertheless not tear or damage the writing surface of paper or other medium.

Other objects and features of the present invention will become apparent from a description of the following embodiments which proceed with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a facsimile apparatus which incorporates the improved stylus of my invention;

FIG. 2 shows a side elevation of a stylus and transducer housing with a stylus constructed in accordance with the present invention;

FIG. 3 is an end elevation view of the stylus and transducer housing;

FIG 4 is an enlarged cross-section view taken on line 4-4 of FIG. 3;

FIG. 5 is a detail view of the stylus of this invention shown detached from the stylus housing;

FIG. 6 is an enlarged detail view of the profile of the writing tip of the stylus; and

FIG. 7 shows the writing tip looking in the direction of the arrow 7-7 in F G 6 DESCRIPTION OF THE PREFERRED EMBODIMENT I In FIG. 1, I have shown a view of a portion of a fac simile transceiver 10 which can utilize the writing stylus in accordance with my invention. The transceiver 10 also include scanning apparatus for of the housing is mounted on a suitable base 11 which supports a plurality of brackets 12. The brackets 12 support a rotating structure for writing (and also for scanning if the facsimile transceiver 10 is used to transmit). 'Ihis rotating structure rotates about a longitudinal axis 13 and comprises a stationary electric drive motor 14. The output from the drive motor 14 is coupled to speed reducing and synchronizing gears 15. The output from the gears 15 rotates a yoke structure generally designated by the numeral operatively connected to the output shaft of drive motor 14. If the facsimile transceiver .10 is used as a transmitter, then the yoke structure 20 may comprise two concave mirrors 21a, 2112 which are symmetrically positioned about the longitudinal axis 13 and which receive light from an incandescent lamp (not shown) whose filament is centered as nearly as possible on the longitudinal axis 13. A set of arms 23a, 23b extend around the mirrors 21a, 21b towards the right, as viewed in FIG. 1, and connect with a mounting block 24. The mounting block 24 rotates with the yoke structure 20, and if the facsimile transceiver 10 is used as a transmitter, carries two scanning lens systems or arrangements 25 (only one of which is visible in FIG. 1), and two writing styli 28a, 28b (stylus 28b is not visible). The facsimile transceiver 10 also includes a suitable enclosure 16 and a cover member which is pivotally or otherwise attached to the base 11 to permit the cover member to be positioned around the rotating structure of the transceiver 10. The cover member has a concave (preferably partially cylindrical) platen (not shown) that receives the paper of copy material to be written upon. When the platen is in its proper position, it curves around the rotating structure and is parallel to the longitudinal axis 13. The platen (not shown) includes means (not shown) for moving the document being written upon in a direction parallel to the longitudinal axis 13.

Both styli 28a and 28b can be mounted upon the rotating structure in the manner disclosed in my copending application No. 778,166, filed Nov. 22, 1968, entitled, Improved Adjustments for Facsimile Receiver Having a Plurality of Writing Styli. This application 778,166 is assigned to the same assignee as the present application. The two styli 28a, 28b are actuated so that the writing tip 30 is moved outwardly against the document at selected times during its rotation in order to produce inscriptions or markings on the pressure sensitive material, this being in response to an electrical signal received from a companion facsimile transmitter. The two styli 28a, 28b in addition to having a precise angular relation to each other, and being in combination with two scanning lens systems, must be compatible with each other and yield consistent and complementary markings for optimum operation. One of the ways of providing proper angular relationship is by a precise positioning adjustment of the relative styli which is the subject of application No. 778,166. My present invention relates to a new and improved configuration and wearability of the writing surface of the two writing styli 28a, 28b so their respective inscriptions are complementary and are substantially identical with each other to extend the useful life of the style.

FIGS. 2 and 3 show side and end elevation views of a stylus and transducer housing having an improved adjustment in accordance with my invention for use with a facsimile transceiver such as shown in FIG. 1. The The housing 35 is preferably constructed from two similar and complementary halves. The complementary halves of the housing 35 when assembled together as shown in FIGS. 2, 3 provide a narrow slot or air gap 39 having the general shape indicated in the cross-sectional 'view of FIG. 4. The slot 39 receives a stylus actuating armature or coil cord 40, which carries a magnetic coil or winding which, when energized, reacts with a magnetic field (such as provided by permanent magnets) to cause the armature 40 to move in an upward direction as viewed in FIG. 4. A stylus 44 is pivotally positioned in the upper portion of slot 39 and is pivoted on a pivot and urged in a downward direction by a spring 46. The upper end 41 of the armature or coil cord engages or rests against the end of the stylus 44 near its writing point 30. When the magnetic winding on the armature or coil cord 40 is energized by an electrical signal from a distant facsimile transmitter, the armature 40 is moved in an upward direction, as viewed in FIG. 4. This movement causes the writing point 30 of the stylus 44 to press against the pressure sensitive material and thus produce the facsimile copy. When the magnetic winding of the armature 40 is deenergized, the spring force on the stylus 44 causes the stylus point 30 to move downward. The stylus and transducer housing 35 may be attached to the block 24 of FIG. 1 inany suitable manner, as for example by the flanges provided on the housing.

Referring to FIGS. 5, 6, and 7 which refer to detailed views of the stylus, the writing surface 69 is of rectangular configuration as illustrated by FIG. 7 and may be of any suitable hard and durable material or alloy having high wear resistance characteristics, such as for example: carbide alloys and compositions, sapphire and diamond.

The writing tip 30 is substantially fiat and the rake angle defined by side 70, is approximately degrees in order to reduce the effect of wear. That is to say, the plane of wear to the surface 69 is at approximately a 90 degree angle to the trailing edge or side 70 of the stylus tip therefore, as the flat surface 69 of the writing tip of the stylus wears, there is less change in the cross-sectional area of the surface or its configuration. Obviously, if the angle is substantially changed to become either arcuate or obtuse then one of the effects of wear will be to change the effective writing area of the writing tip. The 90-degree rake angle is preferred but some deviation is permitted.

It has been found that over the wear life of the stylus that by configuring the rake angle in this manner it is possible to obtain a stylus which is minimally affected by the degree of wear of the writing surface, thus two styli can operate with greater coordination in spite of some degree of uneven wear of a pair of styli. The problem of uneven wear can occur in the case of a radiused stylus (meaning a stylus with a curved writing surface) and in that case such a surface will not operate in phase with its companion stylus. When uneven wear occurs with radi used tip styli, these respective areas differ as a consequence of the differential wear and they no longer function together in phase nor provide identical marking. The advantage of the present invention is that the total marking on the sheet of paper is the combined effect of the respective styli, and they work in coordination with each other with their inscribing effects being closely identical regardless of differential wear. The present invention provides for the possibility of different wear rates without introducing factors of disparity in writing effects as a consequence of different wear rates of the respective styli.

The lead angle of the writing tip, as shown in FIG. 6 is defined by surface 72 and the writing surface 69 is approximately 16 degrees. The lead angle is of importance since it relates to the tendency of the stylus to produce a tearing or other adverse effect on the pressure sensitive material such as the aforementioned carbon paper. An angle of 16 degrees was found to be optimum. Angles substantially less than 16 degrees tend to have the effect of reduced definition of marking by the carbon as the writing tip bears against the writing surface. When the lead angle is too great; that is to say, if the lead angle is substantially greater than 16 degrees a cutting or tearing of the carbon or inscription surface tends to occur.

By way of an example of a particular stylus configuration which has been manufactured and which has proven satisfactory in apparatus of the class described, I produced styli having a lead angle of 16 degrees and with a 0.003 inch length flat or writing surface on the stylus writing tip and having a 90-degree rake angle. The composition of the writing tip is 13 percent cobalt binder and 87 percent tungsten. A typical width of the crest or writing tip is approximately 0.012 inch.

A useful life of the stylus can be projected wherein the writing surface can be worn down to a flat having a new length of approximately .012, this being the equivalent of in excess of 500 hours usage. This represents a more than tenfold increase of wear life of previously used styli. The stylus can be easily replaced and matched With an existing stylus already present in the machine or two replacement styli can be inserted both of which have substantially fiat writing tips which can be expected to have an almost immediate in-phase or matched operation.

Because a fiat is originally provided on the writing tip rather than a radiused surface, two matched styli can be expected to operate in coordination with each other and with minimal phase adjustment requirements during styli wear. Also, the wear rate is itself reduced thus enabling a longer service life and there is a much reduced incidence of degradation to the reproduced copy. Wear which does occur to the stylus is insubstantial and even should one stylus wear at a different rate from the other this does not introduce undesirable phasing effects.

The stylus of this invention can be used in numerous devices and apparatus, and I do not intend to limit the field of use only to the facsimile receiver described herein. Other apparatus are also in need of improved styli, and my invention can be utilized in other such apparatus with equally good results and for the same structural and functional reasons.

Although the present invention has been illustrated and described in connection with single-example embodiment it will be understood that this is illustrative of the invention and is by no means restrictive thereof.

Those skilled in the art can be expected to make numerous revisions and adaptations of the invention, and it is intended that such revisions and adaptations will be included within the scope of the following claims as equivalents of the invention.

What is claimed is:

'1. An improved stylus for use with pressure sensitive media for producing intelligible markings comprising: an arm having a mounting portion on which said arm is movable responsibly to an input force which acts against said stylus to effect a marking operation and a stylus tip adapted to effect inscriptions and including a rectangular inscribing surface, a shank portion of said arm having an acute lead angle to said inscribing surface and a rake angle approximately perpendicular to said inscribing surface.

2. The stylus construction of claim 1 wherein said tip is of a relatively hard and nonweara'ble composition comprised of tungsten-cobalt material.

3. The stylus configuration of claim 1 wherein said tip of rectangular configuration is of substantially flat surface to the material inscribed.

4. A stylus construction usable in a facsimile receiver having stylus carrying means which rotates one or more stylus in spaced relation to each other on said carrying means, and means operative responsively to electrical signals for actuating said stylus or styli, each such stylus comprising:

(a) an arm;

(b) mounting means on said arm forming a pivot whereby said stylus is angularly actuated to effect inscribing operations;

(c) a rectangular writing tip of substantially fiat surface and of hard durable composition;

(d) a shank section connecting said arm and said writing tip and having a lead angle and rake angle of a configuration which reduces damage to the inscription surface and to minimize effects of wear of such writing tip.

5. A stylus construction in accordance with claim 4 wherein said lead angle is an acute angle to the writing tip surface and a rake angle approximately perpendicular to said writing tip surface.

6. A stylus in accordance with claim 4 in which said tip is comprised of a material selected from the group consisting of tungsten-cobalt alloy diamond, sapphire, carbide materials.

7. A stylus in accordance with claim 5 wherein said writing stylus is matched with a second stylus, each such stylus being coordinated and operative together to pro- I vide inscriptions.

References Cited UNITED STATES PATENTS 2,581,616 1/1952 Young 346-112 2,659,652 11/1953 Thompson 3465O 3,149,902 9/ 1964 Dransfield 346- 3,223,029 12/1965 Simshauser 346141X JOSEPH W. HARTAY, Primary Examiner 

